package demo14;

/**
 * Created by Administrator on 2017/6/20.
 */
class Quadrangle2{
    public static void draw(Quadrangle2 q){

    }
}
public class Parallelogram2 extends Quadrangle2{
    public static void main(String[] args) {
        draw(new Parallelogram2());
        Quadrangle2 q = new Parallelogram2();
        Parallelogram2 p = (Parallelogram2)q;
    }
}
